Chicago’s ABC 7 News reports that an extra on the set of Transformers 3 suffered a head injury on the last night of shooting in the city:

A 24-year-old woman participating in a car stunt suffered a serious head injury during a ‘Transformers 3′ shoot in northwest Indiana one day before filming was supposed to conclude in the Chicago area.

Extra Gabriela Cedillo was injured on the set Wednesday night along a stretch of Cline Avenue, which was closed to traffic for filming, in East Chicago.

A stunt was apparently being performed during filming when Cedillo, who is not a stuntman, was hurt.

The vehicle was being towed by another vehicle," said fellow extra Blaine Baker. "The cable between the two vehicles broke. It whipped around and sliced through the woman’s car and sliced through her skull, apparently."

Reports say that today’s shooting in Chicago has been cancelled. You can watch ABC 7’s report on the matter using the player below: